Model manager attributes

[Naveen Yadav]

I have few questions about manager class

creation_counter is used to keep track of Manager's instance being created, what is the motivation behind this ?
and
what is the purpose of check() which returns empty list ?


Thanks.

[Tomer Chachamu]

check() is called here: https://github.com/django/django/blob/d7b9aaa366dd54ecc3142c588162e3adc7c2f7ac/django/db/models/base.py#L1265

It can be used to implement configuration checks. https://docs.djangoproject.com/en/1.11/topics/checks/#field-model-manager-and-database-checks

creation_counter appears to be used to make sure the managers are always initialised in the same order as they were defined in the model (for models that use multiple managers).

https://github.com/django/django/blob/a4092af3d33b2e7a5f05f6be3bdf8298d32d9ff8/django/db/migrations/state.py#L526